Hello
If it is a prolonged sensitivity for more than few seconds then your pulp has been damaged or inflamed. Kindly consult a root canal specialist ( Endodontist ) and get a X-ray with clinical evaluation done. Most of the times such cases can be treated easily and the pain subsides immediately after treatment.
Next Steps
Consult an Endodontist urgently before it becomes unbearable.
Health Tips
Avoid eating or drinking from that side